Electrical time switch with indicator



APril ,4 964 w. HOLZER 3,130,279

ELECTRICAL TIME SWITCH WITH INDICATOR Filed Aug. 12, 1960 INVENTOR WALTER HOLZER WWW ATTORNEYS United States Patent 3,130,279 I ELECTRICAL TIME SWITCH WITH INDICATOR Walter Hoizer, Shutzenrain, Meershurg am Bodensce, Germany Filed Aug. 12, 196i), Ser. No. 49,298 3 Claims. (Cl. Mill-38) The present invention relates to an electrical time switch with indicator, particularly, to an electrical time switch which is adapted to turn on an electrical apparatus such as an electric stove, a range, an oven etc. at a predetermined time and to turn this apparatus off after a predetermined period of time has elapsed.

Electrical time switches are known in the art as being provided with a clockwork producing automatic switching operations. In general, the known electrical time switches have the disadvantage that they can be read only under favorable light conditions and only from a very close position. In particular, it is usually difficult to read how long it will take when the turn-on operation will occur, and, later, how long a time interval will pass until the time switch turns the apparatus off automatic 'ly. The present inventionovercomes these deficiencies.

According to one aspect of the present invention in a preferred embodiment thereof it is suggested to use a rotatable shaft driven by a clockwise or the like; a transparent disc is secured to this rotating shaft; switching or actuating discs are positioned in axially spaced relationship to the driving disc, and they are frictionally engageable with this driving disc; the switching discs have a semi-opaque sector and a translucent sector; means are provided to adjust the position of the switching discs relatively to the rotating shaft and the driving disc. Fur ther means are associated with and connected ,to the switching discs to operate electrical switching means whereby during an operation of such electrical switching means the switching discs are positively engaged therewith and come to a full stop. A light source is provided behind the discs and light rays pass through all of them. These light rays are affected differently when they pass either through the translucent or the semi-opaque sectors of the various discs, whereby visible sectors of different degrees of translucency are defined. Particularly, the sector having greatest magnitude of overall translucency is to indicate the time period during which the apparatus controlled by the electrical time switch will be turned on.

It is a primary object of the present invention to provide a new and improved electrical time switch which can be read from a longer distance even under unfavorable light conditions whereby in particular at any given moment the time interval during which the apparatus will be or remain turned on is very clearly indicated.

It is another object of the invention to provide a new and improved electrical time switch having a very simple construction and can be easily manufactured at an economical cost.

'While this specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the object of the invention and further objects and advantages thereof will be better understood from the following description taken in connection with the accompanying drawing in which:

FIG. 1 is a partially cross-sectional, partial side view of an electrical time switch according to the present invention;

FIG. 2 is a front view particularly of the indicating elements of the time switch shown in FIG. 1 and FIG. 2a illustrates an enlarged portion of a detail of the time switch shown in FIGS. 1 and 2. I

In FIG. 1 a minute shaft 1 is driven clockwise by a suitable clockwork 16 of any type, preferably an electric motor. Shaft 1 is provided with an adjustment handle 11: for the clockwork which handle may also serve as minute hand. Shaft 1 is received in a hollow shaft 10 which serves as hour shaft and is also driven by the clockwork 16 but in a counterclockwise direction. A transparent disc 2 is secured to shaft 10 and rotates therewith. Disc 2 is provided with a dial, including index markers 1 to 12 or 1 to 24 arranged circularly around the axis of. shaft 10, which is also the center axis of disc 2. Actuator or switching discs 5 and 7 are loosely seated on shaft 10 at both sides of disc 2. Discs 5 and 7 are urged towards each other and towards the disc 2 by means of membrane springs 8 and 9, respectively, which membrane springs are supported on shaft 10 by means of supporting or clamping rings 8a and 9a, respectively. Disc 2 is further provided with friction coatings or friction rings 3 and 4.

These friction rings 3 and 4 are shown in cross-section in FIG. 1 and they serve also as spacers between disc 2 and discs 5 and 7,respectively. The friction coatings may be provided by means of a foaming up process upon the disc 2. Alternatively, these friction coatings or rings may be provided during the manufacturing of disc 2 which is preferably made of plastic whereby a coarse pressure process forms such friction rings as integral parts of disc 2 so that the costs of manufacturing are greatly reduced.

In a modification it is possible not to deposit the frie tion coatings on the disc 2 but on the inner side of the two discs 5 and 7. In this case the friction coatings on discs 5 and 7 may also be obtained by means of a foaming up process or by coarse pressure whereby these discs 5 and 7 preferably are also made of plastic material. Disc 2, friction coatings orrings 3 and 4, discs 5 and 7, and membrane springs Sand 9, together form two slip friction clutches. Disc 2 is the driving member of these clutches, and upon the membrane springs urging the discs 5 and 7 against disc 2 the former will follow the rotation of the latter as long as these discs 5 and 7.do not encounter any resistance overcoming the frictional engagement.

The discs 5 and 7 furthermore are provided with lugs 30 and 31, respectively moving therewith. These lugs protrude beyond the outer circumference of the discs. A stationary stop-switch actuator 11 is positioned above the top of the preferably vertically positioned discs 2, 5 and 7. This stop-switch actuator 11 includes two stems 11b and He protruding from and moving in a horizontal direction with respect to the housing of stop-switch actuator 11.

The stems 11b and 11c are positioned in the path of the lugs 36 and 31, respectively. Upon rotation of discs 2, 5 and 7, the lugs 30 and 31' at given time instances will reach the stems 11b and 110, respectively. Any of the lugs 30 and 31 engaging its associated stem will be forced to stop. Such stoppage, however, does not stop disc 2 and therefore thedisc which, has been stopped is disengaged. from the driving disc 2, and the thus disengaged clutch is in its slipping mode. The stop-switch actuator 11 is further provided with a hand 11a protruding down wardly inside of the space between the discsS and 7. As it can be seen from FIG. 2 this staionary hand 11a serves as hour hand indicating the hour at the rotating dial associated with the driving disc 2. In FIG. 2 is further illustrated that the stem 11b does not only serve as a stopping means for its associated disc 5, but that the lug 30 imitates a switching action when it reaches the stem 11b. The broken open view of stop-switch actuator 11 in FIG 2a illustrates that inside of actuator 11 two stationary contacts 41 and 42 are positioned in spacial relationship, and they may be overbridged by a movable contact bridge 43 which is mounted on the portion of stem 11b which is positioned inside of the housing of actuator 11. A spring 44 normally places the contact bridge 43 in a disengaged position and defines a definite rest position for stem 11]). When the lug 30 reaches stem 1111 the contact bridge $3 is urged towards the contacts 41 and 42 against the tension of spring 44. When the contact is closed a definite stop for the stem 11b and there fore for lug 3t) and in turn for disc 5 is reached. Contacts 41 and 42 are electrically connected to conductor wires 45 and 46, respectively, which are only shown schematically in FIG. 2. These conductor wires 45 and 46 are part of an electrical circuit, for example, a switching circuit of an electric oven. The closing of the contacts d1, 42 and 43 turns such oven on. In open position, contact 43 is spaced from contacts 41 and 42 by a small distance only, sufiicient to prevent a spark discharge. Such small distance thus defines avery small operating path for stem 11b when actuated by lug 3t It will be appreciated that stem file is also associated with an electric contact device which corresponds to the contact device associated with stem 11b. The only difference between the thus defined circuits is that the electrical output of the contact device associated with stem 110 is led to an actuating member of the oven which turns it off.

From the foregoing, it will be understood, that disc 5 can be called switching-on disc while disc 7 can be called switching-off disc.

Discs 5 and 7 are optically divided into sectors whereby one sector is substantially translucent 5b and 7]) respectively, while the other sector 5a and 7a of each disc is substantially opaque or preferably semi-opaque. The borderline dividing disc 5 into a semi-opaque and translucent sector is provided with an index marker 12 which preferably is completely opaque. A similarly completely opaque marker 13 is provided at the borderline of translucent and semi-opaque sectors of disc 7. The lugs 3i) and 31 are positioned where the borderlines as defined above reach the circumference of their associated discs 5 and '7, respectively. For facilitating the operation of the time switch preferably the words on and off are opaquely written on the discs 5 and 7, respectively, adjacent the markers 12 and 13, respectively.

The discs 5 and '7 may also be rotated manually for adjustment purposes. For example, the lugs 30 and 31 can be used as handles. In this case it is advisable to have either the stems 11b and 110 or the lugs 39 and 31 or all of these elements made of electrically insulating material. The adjustment is simply carried out in manually overcoming the frictional engagement of disc 2 and any of the discs 5 and 7.

FIG. 1 further illustrates an alternative additional mode of adjusting the position of discs 5 and '7 with respect to disc 2. A friction wheel 25 is secured to a shaft 26 which may be shifted in the two axial directions inside of the stationary frame 27. Coil springs 28 and 29 normally keep the friction wheel 25 in a central position inside of frame 27. The shaft 26 may be rotated by means of a knob 32. For adjusting the position of disc '7 the shaft 26 will first be pushed in axial direction in accordance with the upper one of the two arrows until the friction wheel 25 engages disc '7. Then knob 36} will be rotated until disc 7 has the desired position during which rotation the frictional engagement of disc 7 and disc 2 is to be overcome. If one desires to adjust the position of disc 5, the shaft 26 will be pulled in the direction of the lower one of the two arrows until friction wheel 25 engages the edge of disc 5. Thereafter the knob 32 will be rotated until disc 5 has the desired position during which rotation the frictional engagement of disc 5 and disc 2 is to be overcome. As the operator releases the knob 32 the springs 28 and 29 cause the friction wheel 25 immediately to disengage the disc with which 4 it was engaged, and wheel 25 assumes its resting position between the edges of discs 5 and 7.

The illustrated time switch further includes a stationary light source 18 positioned behind clockwork 16. The light rays are reflected by the inner surface 19 of a stationary frusto conical mirror 20. The reflected light passes substantially undiminished through sector 7b of disc 7, but it is partially absorbed in the shaded, semiopaque sector '70 thereof; any light passing through disc 2 remains substantially undiminished with the exception of the opaque dial numbers which have a clearly visible contrast with respect to their immediate vicinity. Finally, the light passes through disc 5 and is partially absorbed by semi-opaque sector 5a but it will not be absorbed by translucent sector 512.

From the foregoing it will be understood, that the sector defined by the overlapping portions of translucent sectors 5b and 7b is clearly visible as an image indicating the radial displacement of discs 5 and '7 from each other. Furthermore, the relative position of the thus defined translucent sector with respect to hand 11 indicates at any given moment how long it will take for the switching operation to commence. The semi-opaque sectors 5a and 7b primarily serve to enclose the completely translucent sector as a sufficiently contrasting mark r; these semi-opaque sectors, however, still make it possible that one can read the entire dial of disc 2.

The arrangement as described thus far operates as follows: clockwork l6 drives the shafts 1 and lit in the manner of an ordinary clock, whereby hand la and disc 2 with its associated dial rotate about the center axis of the shafts. In the position shown in FIG. 2 the time indicated is about twelve thirty. As the operator, for example, a housewife, desires to have the oven turned on at a particular time, she rotatably adjusts disc 5 to the desired position as outlined above by means of knob 32. This desired position as adjusted is indicated by marker 12. In FIG. 2 is shown that disc 5 has been set for a turning on operation at about twenty minutes past one. Furthermore, disc '7 has been set to a position in which the marker 13 indicates a turn off time of about ten minutes to three. A completely translucent sector defined between the markers 12 and 13 and their associated border lines separating translucent and semi-opaque portions of each of the discs, indicate the time period of eightly minutes during which the oven will be turned on. Now time proceeds and the driving disc 2 rotates in a counterclockwise direction whereby switching discs 5 and 7 follow this rotation due to their frictional engagement with disc 2. After about fifty minutes, the lug 31) will reach stem Illb and move it until the contact piece 4-3 positively engages the contact pieces 41 and 42. At that moment, the oven will be turned on and the disc 5 will be stopped and retain its position. Disc 7, however, has not been stopped and remains in frictional engagement with disc 2 and therefore it will continue to move. During this continued movement of discs 2 and 7, disc 5 remains stationary, and the translucent sector defined between markers 12 and 13 will gradually be decreased. At any time the decreasing width of this translucent sector will indicate the remaining time during which the oven will remain in a turned-on position. Gradually lug 31 approaches stern 11c, and upon engagement therewith at two forty the oven is turned off. At this time the translucent sector will vanish. The movement of disc '7 is yet stopped due to a positive engagement of lug 31 and stem 11c overcoming the frictional engagement of disc 2 and disc 7. Disc 2, however, will continue to rotate while disc 5 and disc 7 remain stationary until lug 3t) and 31 are removed from their engaging position by rotating discs 5 and 7 in a clockwise direction as indicated above, for example, by operating knob 32.

It will be appreciated that the device described above is not limited in its application to household articles like an oven, but that this time switch can be used in any field where it is desired to have a particular process of operation turned on at a given time and turned off at a succeeding time period. The period of time during which the control device is held in turn-on position is indicated by the width of an easily recognizable translucent sector.

This application is a continuation-in-part application of application Serial No. 701,210 of applicant, now

abandoned, and it is not limited to the embodiment described above, but all changes and modification thereof not constituting departments from the spirit and scope of the invention are intended to be covered by the following claims.

What is claimed is:

1. An electrical time switch actuator comprising, in combination a rotating shaft; a substantially translucent driving disc secured to said shaft and rotating therewith; two switch actuating discs loosely seated on said shaft for independent rotation and adjustment and being disposed at both sides of said driving disc, each one of said actuating discs having two sectors of different light transparency; slip frictional means interposed between said discs for frictionally engaging separately said driving disc and said actuating disc; and stationary switching means actuated by said actuating discs and selectively stopping one of said actuating discs from rotating while the other disc continues to be rotated by said driving disc.

2. An electrical time switch actuator comprising, a clockwork; a shaft driven by said clockwork; a translucent driving disc secured to said shaft and rotating therewith, said driving disc carrying an hourly dial; two switching discs loosely seated on said shaft for independent rotation and adjustment and being disposed at both sides of said driving disc, each one of said actuating discs being divided into two sectors of ditferent light transparency; frictional means for slip frictionally engaging separately said driving disc and said switching discs, contact actuators mounted on said switching discs; and stationary switching means actuated by said contact actuators and selectively stopping one of said switching discs from rotating while the other switching disc continues to be rotated by said driving disc.

3. An electrical time switch actuator comprising, in combination: a rotating translucent hour dial indicator, a first and a, second switch actuator positioned in front and behind said rotating dial, respectively, said switch actuators having sectors of different light transparency; first friction means for engaging said dial with said first actuator; second friction means for engaging said dial with said second actuator; means for individually adjusting said switch actuators relative to and by disengaging them from said rotating dial indicator; switching means associated with said actuators and operated therefrom, said switching means selectively stopping one of said actuators from rotating while the other actuator continues to be rotated by said rotating dial; and a light source placed behind said actuators and said disc to pass light therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 1,575,637 Neth Mar. 9, 1926 2,364,988 McFarland Dec. 12, 1944 2,374,590 Dubham Apr. 24, 1945 2,502,985 Paulson Apr. 4, 1950 2,520,028 Biskind Aug. 22, 1950 2,742,015 Hoyle Apr. 17, 1956 2,745,918 Stewart May 15, 1956 2,862,376 Thelander Dec. 2, 1958 2,886,106 Gallagher et a1. May 12, 1959 

1. AN ELECTRICAL TIME SWITCH ACTUATOR COMPRISING, IN COMBINATION A ROTATING SHAFT; A SUBSTANTIALLY TRANSLUCENT DRIVING DISC SECURED TO SAID SHAFT AND ROTATING THEREWITH; TWO SWITCH ACTUATING DISCS LOOSELY SEATED ON SAID SHAFT FOR INDEPENDENT ROTATION AND ADJUSTMENT AND BEING DISPOSED AT BOTH SIDES OF SAID DRIVING DISC, EACH ONE OF SAID ACTUATING DISCS HAVING TWO SECTORS OF DIFFERENT LIGHT TRANSPARENCY; SLIP FRICTIONAL MEANS INTERPOSED BETWEEN SAID DISCS FOR FRICTIONALLY ENGAGING SEPARATELY SAID DRIVING DISC AND SAID ACTUATING DISC; AND STATIONARY SWITCHING MEANS ACTUATED BY SAID ACTUATING DISCS AND SELECTIVELY STOPPING ONE OF SAID ACTUATING DISCS FROM ROTATING WHILE THE OTHER DISC CONTINUES TO BE ROTATED BY SAID DRIVING DISC. 